Door-check.



J. C. SCHMIDT.

DOOR CHECK.

APPLICATION FILED DEC.20. 1913- Patented Sept. 28, 1915.

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noon-annex.

Specification of Letters Patent.

Patented Sept. 28, 1915.

Application filed December 20, 1913. Serial No. 807,805.

To all whom it may concern Be it known that 1, JOHN C. SCHMIDT, citizen of the United States, residing. at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Door-Checks, of which the following is a specification.

This invention relatesto door-checks and co-acting plungermembers so that lost mo tion and resultant pounding of the parts is eliminated; a plunger and casing construc, tion whereby the former is supported at three points, thus overcoming the tendency of the plunger to buckle or bend when excessive strains are applied thereto, a simple and economical construction generally which secures easeof operation and durability.

A preferred embodiment of my present invention is illustrated in the accompanying drawing, in which Figure 1 is a partial top-plan view of the casing and the arm whichengages the upper end of the plunger; Fig. 2 is a longitudinal section onthe median line of the complete door check and closer; and-Fig. 3 is a detail in elevation of the plunger cam-merit bers, showing them separated or in a position opposite to that indicated in Fig. 2.

Referring to the details of the drawing, the reference numeral 4 indicates a cylindrical casing open at both ends, 5, a cover plate secured to the upper end of the casing by'screws, and 6, a cupshaped plate screwed into the lower end of the casing and forming The lower portion of a closure therefor. the casing is of less cross-diameter than the upper part, and is machined to provide smooth-walled liquid rece1v1ngchamber 4*.

Extending into the upper chamber, 4, the casing is cast wi'tlran annular Wall 4*, the upper portion'of which terminates in a neck t", the end of which is beveled to'aflord a seat for a feltwaslIer 4:. Where the wall 4:?

contracts to form the neck 4, two small holes i are countersunk in the inner face, to

receive or seat corresponding studs 7, on the ad acent face of the upper cam 7 which fits snugly and non-rotatively within the annular chamber circumscribed by the wall 4?. The cam 7 is cast with an annular extension 7 which fitssnugly within the neck 4 and has its end beveled to receive the washer 4 Arranged below the cam 7, is acomple mentary cam 8, the faceof which inclines oppositely to the face of the former, soxthat the rotation of the latter relative to the cam -7, which is non-rotatable, causes a longitudinal movement of the cam 8, and the members connected therewith.

To effect desirable wearing conditions,- I place between the cam-faces of the two earns,

a ring 9, of phosphor-bronze, brass or other suitable material.

The cam 8 is pinned to the plunger stem 10, by a pin 8? which passes through holes provided therefor in the cam and stem;

The plungerstem 10, is a cylindrical bar ofsteel, with a bore 10 extending its entire length, which bore is reduced, as at 10",

to provide a seat for the needle-valve 14 which extends upwardly through the bore 14:. The valve stem is threadedat its upper end l t, to receive a nut 15, which is also externally threaded to engage the threaded I counterbore in the upper end of the plunger stem 1O. The stem 10 has attached thereto by a driving fit, a piston, made up of a disk 11, an expension ring 12,-fitte'd to the disk and a brass or bronze ring-nut 13 which has a threaded engagement with the disk. The disk has an opening 11, which serves as a passageway for liquid from one side of the piston to the. other, and said opening is provided with seats for a ball-valve ll loosely arranged therein. Above and below the piston, the stem 10 is provided with horizontal ports 1O, 10, respectively, which extend from the outer surface to the bore 10*, 10 and with the latter, form a passageway for the liquid as it flows from one side of the piston to the other. The inner end of the port 10 is partially covered by the tapered lower end 14- of the valve 14, so that the rapidity of the flow of liquid is controlled by the vertical adjustment of said valve, though it cannot be entirely out off.

'16 represents a collar which fits between fitted tothe upperedge 21' of the extenof the casing 1 below the cover-plate The plate has oppositely placed notches 16 in its periphery, and on its under surface is formed witha rib, 16. A stud 17 is fixed in an opening 16 and projects downwardly and in'turn ser-ves to maintain a washer 20 in close engagement with the felt washer 4 sion 4.

22 represents the innermember of the two levers which connect the plunger .with a door, and it is not shown in full becauseth e general form and the functions of such mem- .bers are well understood. The features which I have modified are in slotting the end of the lever-arm to provide a rectangular socket 22 to receive the squared upper end of the plunger, and as at 22* to receive gage radial teeth 16 on the upper edge of. the collar 16, when the latch is in the horia latchQeLwhich is pivoted on-a pivot bolt 23 extending transversely of theslotadja- 7 cent the stem. The latch is formed with a' cam extension 24?, which is adapted to enzontal position shown. The latch is also formed with an extension 24* at its free end which facilitates the lifting of the latchwhen it is desired to disengage it from said teeth, a

At a short distance below its upper end, the plunger stem is formed with an annular groove 10 which is adapted to receive a two-piece collar 25, which serves as a key and is held in place by abutting shoulders on the stem and collar 16 respectively.

As shown in Fig. 2, the spring 18 is under partial compression and the plunger in its raised position, thustbringingthe cams 7 8, together Now if the arm 22 is moved in the direction indicated by the arrow in Fig. 1, the spring will be given a torsional or winding-up movement by the rotary movement of the plate 16, and will also be increasingly compressed by the longitudinal.

movement of said plate incident to the movement of the cam 8 downwardly. relative to the'cam 7. If the chamber l is filled with glycerin or other suitable liquid, it is obviliquid will also lubricate .the cam 8 and its bearings;

As the cams 7f8 are constantly held in close frictional contact With the ring9, by the compressed spring 18, it will be obvious that all 'wearof said'parts will be automatically taken up, and thus there will be no possibility of the lost motion and resultant pounding above alluded to as common to It Will'also be' large spring, and the walls 4 form a guide 1 a 85 for the spring. 'Having thus described my invention in one of its forms, what I claim is 1. In a door check and closer, a. casing having a spring compartment and a liquid compartment, a cap for saidv springcompartment having a central opening therein, a spring disk having a flange therein adapt ed to extend through'and having its bears.

ing' in the opening in said cap, a spring within sald spring compartment secured re spectively to said compartment and said movement thereof, a cam faced disk arranged in said liquid chamber and around said stem and through which said stem is adapted to reciprocate, a second cam faced disk, a rotatable and reciprocable stem jourdisk fixedly arranged on said stem within the liquid compartment and adapted to coact with said first mentioned cam, a piston arranged on said stem within said liquid compartment, said plunger stem having a passageway therein opening respectively above and below said piston, a needle valve extending longitudinally of said stem and adapted to control the size .of said passage way.

2. In a, door check and closer, a casing having a spring compartment and a liquid compartment, a cap for said spring compartment having a central opening therein, a spring disk having a flange therein adapted to extend through andhaving its bearing in the opening in said cap, a spring within said spring compartment secured respectively to said compartment and said disk, a rotatable and reciprocable stem journaled centrally ofsaid'spring cap and extending to and through said fluid chamber, a cap adapted to close said fluid chamber having a central aperture therein into which the lower end of said stem extends and which is adapted to form a bearing for the movement thereof, a spring actuated collar surrounding said stem for separating said liquid chamber from said spring chamber, a cam faced disk arranged in said liquid chamber and around said stem and through which said stem is adapted to reciprocate, a second cam faced disk fixedly arranged on said stem within the liquid compartment and adapted to coact with said first mentioned cam, a piston arranged on said stem within said liquid compartment having a passageway therethrough and a valve in said passageway adapted to close same against the passage of liquid upwardly therethrough, said plunger stem having a passageway therein opening respectively above and be low said piston, a needle valve extending longitudinally of said stem and adapted to control the size of said passageway.

3. In a door check and closer, a casing having a spring compartment and a liquid compartment, a cap for said spring compartment having a central opening-therein, a spring disk having a flange therein adapted to extend through and having its bearing in the opening in said cap, a spring within said spring compartment secured respectively to said compartment and said disk, a rotatable and reciprocable stem journaled centrally of said spring cap and extending to and through said fluid chamber, a cap adapted to close said fluid chamber having a central aperture therein into which the lower end of said stem extends and which is adapted to form a bearing for the movement thereof, a cam faced disk arranged in said liquid chamber and around said stem and through which said stem is adapted to reciprocate, a second cam faced disk fixedly arranged on said stem within the liquid compartment and adapted to coact with said first mentioned. cam, a piston arranged on said stem within said liquid compartment, said plunger stem having a passageway therein opening respectively above and be low said piston, a needle valve extending longitudinally of said stem and adapted to control the size of said passageway, and means for normally holding the above mentioned spring under partial compression.

In testimony whereof I affix my signature in the presence of two witnesses.

JOHN C. SCHMIDT.

Witnesses:

VVM. HAROLD EIC-HELMAN, M. A. MILORD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

